This specification relates generally to testing the compatibility of client devices with web services.
Web services generally provide messages to client devices according to a schema that defines constraints for the content and structure of the response messages. For example, a web service can provide responses to requests received from client devices, with the responses satisfying the constraints specified by the schema for the web service. If a client device experiences a failure when processing a message received from the web service, the experience of a user of the client device may be undesirably affected.